|Builder:||William Beardmore and Company, Dalmuir|
|Laid down:||7 July 1917|
|Fate:||Sold for scrapping, February 1939|
|Class and type:||L-class submarine|
|Length:||235 ft (71.6 m)|
|Beam:||23 ft 6 in (7.2 m)|
|Draught:||13 ft 2 in (4.0 m)|
|Range:||4,500 nmi (8,300 km; 5,200 mi) at 8 kn (15 km/h; 9.2 mph) on the surface|
|Test depth:||150 feet (45.7 m)|
L52 and its successors were modified to maximise the number of 21-inch (53.3 cm) torpedoes carried in the bow. The submarine had a length of 235 feet (71.6 m) overall, a beam of 23 feet 6 inches (7.2 m) and a mean draft of 13 feet 2 inches (4.0 m). They displaced 914 long tons (929 t) on the surface and 1,089 long tons (1,106 t) submerged. The L-class submarines had a crew of 44 officers and ratings. They had a diving depth of 150 feet (45.7 m).
For surface running, the boats were powered by two 12-cylinder Vickers 1,200-brake-horsepower (895 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600-horsepower (447 kW) electric motor. They could reach 17 knots (31 km/h; 20 mph) on the surface and 10.5 knots (19.4 km/h; 12.1 mph) underwater. On the surface, the L class had a range of 4,200 nautical miles (7,800 km; 4,800 mi) at 10 knots (19 km/h; 12 mph).
The boats were armed with six 21-inch torpedo tubes in the bow. They carried eight reload torpedoes for a grand total of a dozen torpedoes. They were also armed with two 4-inch (102 mm) deck guns.
HMS L69 was laid down on 7 July 1917 by William Beardmore and Company at their Dalmuir shipyard and launched on 6 December 1918. She was then towed to HM Dockyard, Rosyth for completion on 18 April 1923. The boat was sold to Arnott Young in February 1939 for scrap.